She tweeted: "Still so overwhelmed by all the love and well wishes we have received from you all... my heart is so full."

Meanwhile, E! News reports that the storylines of the hit musical comedy series will now be changed because Cory's character Finn would have been in the final two episodes of the season.

The season finale will revolve around New Directions competing at Regionals, and production is set to wrap no later than April 24.

A show source said: "Most of the cast didn't know there was any problem and many of them are surprised. Everyone seems to support his decision to get help and to not delay it."

Cory, 30, entered rehab earlier this week. His representative told People magazine that he had "voluntarily admitted himself to a treatment facility for substance addiction".

The star also had treatment when he was 19 and has previously spoken about his addiction struggles, saying he had a serious problem and took just "anything and everything". In 2011 he told Parade he was "lucky to be alive".

After the news emerged, Lea, who plays Rachel on the programme, told People she was "proud" of Cory's decision.

"I love and support Cory and will stand by him through this," said the 26-year-old. "I am grateful and proud he made this decision."